A ban on hotlinks

At least one major site is hotlinking to the wiki download area.
That is - that site has a download button which lets users download a file from my server without ever seeing this wiki.
That site is also plastered in advertising so they get revenue while we don't.
We get zero benefit from hot links, we don't get viewers from it.

They do have a small text reference to our site (not a clickable link) so we do get some referrals but most people just grab the file.

The other problem is their information is out if date. Visitors would be better off with a shorter description of the project and a link to the wiki page.

I'm not sure what is considered fair use these days but I think I will be enabling hotlink protection some time soon. Not just on binaries but also images and maybe avi.

Some of the sites I've downloaded from lately have splash screens and long delays to maximise add exposure.
I won't do this but getting people to at least visit the site to get free downloads seems fair to me.

29-may-08,
Implementing a ban on hotlinks wasn't all that easy.
There is plenty of info out there on preventing hotlinks to static webpage images and tools to do it for you.
In the wiki you have to block URLs which look like this - http://nerdipedia.com/tiki-download_file.php?fileId=59

Basically I check if the referer was nerdipedia in one of it's eight variations.
If it wasn't I check if the script is "tiki-download_file.php"
If so redirect to a 403 error page.
The script to do the magic in the .htaccess file ended up like this.